Drive trains for known vehicles, which trains are outside of the practice are advantageously equipped with frictional based shifting elements (such as disk clutches), by means of which, with the aid of the shifting element possessing an actually adjusted power transfer capability, a torque acting in a vehicle axle running between two powered wheels, can be separated within the limits of the driving conditions.
The power transfer capabilities of the shifting elements, which are mostly designed as lamella clutches, i.e., friction shifting elements, are respectively and advantageously adjusted by an electromechanical actuator, which possesses an electric motor, a gear train operationally bound to the electric motors and which are further in connection with a drive-converter apparatus for the transformation of the rotational acting drive of the electric motor into a translatory activation movement for the control of the related shifting element. In this arrangement, the power transfer capabilities of such frictional shifting elements is increased by way of drive converter activations which are increasing in the closure direction of the shifting element, which is counter to the opening direction of the shifting activity of a spring in the opening direction.
The reversal of the rotary drive of the electric motors into translation, activation motions for the shifting elements is done by way of drive converters, which respectively again possess a first drive element and a second drive element from which the drive element for the control of the shifting element opposite to the respective other drive element is translatorally moveable. In this assembly, the transformation occurs by way of a spindle/spindle nut arrangement, spherical-ramp arrangement by which the operational connection between drive elements can be characterized by defined increasing of the windings or the curve tracks.
In order to hold the operating force of an electric motor to the lowest possible level, upon the closure of a shifting element, the practice has developed such a method that the increase is so to be carried out, that the frictional moment between the drive converter and the shifting elements respectively support the rotational drive of the electric motor.
However this is disadvantageous in that the support of the electric motors assigned to the shifting elements is to be carried out with drive converters of respectively different lead angles, whereby the manufacturing costs of the actuator is raised into undesirable heights.
The present invention has the purpose to make an apparatus for the adjustment of the power transfer capability of two frictionally based shifting elements available, which can be economically manufactured.